Electrolytic unit



Patented July 28, 1942 ELECTROLYTIC UNIT John M. Burkemer and James E.Mason, Tucson, Ariz.

Application June 29, 1933, Serial No. 281,897

3 Claims. (01. 204-248) Our invention relates in general to electrolyticunits for recovering precious metals, such as gold and silver fromphotographic or other baths. These electrolytic units areelectro-couples consisting of layers of different metals, generallycopper and zinc, separated by interjacent layers of porous materials, asdescribed in Patent No. 1,425,935, dated August 15, 1922. However,electrolytic units built in accordance with this patent are slow inaction and of low efficiency, due to the fact that the metal layers ofthese units consist of straight, practically equally sized metal strips,arranged in slightly spaced relation parallel and opposite to each otherso as to prohibit proper exposure of the metals to the solution, and aproper ratio of exposed surfaces of the metal layers to said solution.

The general object of the present invention is the provision of animproved electrolytic unit of the type referred to above, which actsspeedily and is highly eflicient by specific construction, size andarrangement of its metal layers.

Another object of the invention is the provision of an electrolytic unitof the type referred to above which includes relatively wide, oppositelyarranged zinc plates and a rather narrow strip of copper arrangedtherebetween opposite the central portion of the zinc plates, the copperstrip providing a surface substantially smaller than the surface of eachzinc plate so as to effect an eflicient ratio of exposed surfaces of themetal layers of the unit.

A further object of the invention is the provision of an improvedelectrolytic unit of the type referred to with differently sized,alternately arranged layers of zinc and copper which layers areseparated from each other by layers of absorbent material, and in whichthe zinc layers, forming the outer members of the electro-couple,include areas extended beyond the copper layers for better contact ofthese zinc layers with the solution from which the precious metals areto be reclaimed.

Still another object of the invention is the provision of anelectrolytic unit of the type referred to above with zinc layersapproximately three times the size of the copper layer, the zinc layersbeing formed with straight central areas opposite the copper layer andsymmetrically arranged wing portions adjacent and angularly related tosaid central areas, to effect intimate contact of these wing portionswith the solution from which precious metals are to be reclaimed.

In addition the invention has certain other it from presently knownstructures. These improvements embodying certain novel features ofconstruction are more clearly set forth in the following specificationand the appended claims; and a preferred embodiment of the invention-ishereinafter shown with reference to the accompanying drawing formingpartof the specification.

In the drawing:

Fig. 1 is a perspective view of an electrolytic unit embodying theinvention, with some of the elements forming the 'unit shown broken awayto more clearly disclose the construction of the unit.

Figures 2 through 6 show perspective views of the metal elements of theunit; thus:

Fig. 2 is a perspective view of the shim brass covering for one of thezinc plates;

Fig. 3 is a perspective view of the zinc plate covered by the coveringshown in Fig. 1.

Fig. 4 is a perspective view of the copper strip;

Fig, 5 is a perspective view of the other one of the zinc plates, and

Fig. 6 a perspective view of the shim brass covering for the lastreferred to zinc plate.

The electrolytic unit shown in Fig. 1 of the drawing embodies anelectro-couple of two zinc plates 3 and 4 and a copper plate 5 arrangedbetween plates 3 and 4 opposite and parallel to the central portionsthereof. Each of the zinc plates 3 and 4 has approximately three timesthe surface of straight copper plate 5 and is subdivided into threesubstantially equally sized portions, a straight central portion 6 andtwo wing-like portions 1, 1, arranged adjacent to central portion 6 andangularly offset with respect thereto for a purpose later to bedescribed.

The zinc and copper plates 3, 4 and 5 are separated from each other byabsorbent material such as cotton gauze 8 which is preferably foldedaround zinc plates 3 and 4 in such a fashion as to form a pocket 9between central portion 6 of plates 3 and 4 into which pocket copperplate or strip 5 is kept. As shown, zinc plates 3 and 4 are covered andpartly encircled by shim brass sheets l0, which sheets are folded aroundplates 3 and 4 so as to openly expose their inner central surfaces. Shimbrass sheets I!) are also covered with cotton gauze and form neutraldepositary elements for precious metals to be recovered from a solution,and the gauze permits of any deposited material being readily strippedor released from these sheets.

The thus formed electro-couple is securely tied together by means of abrass band I2 fully' enmarked super'iorities which radically distinguishcircling same, which band has its overlappingendsllandllncuredtogetherbyascrew memberll,extendedthroughallmetallayersto.

electrolytic unit is placed into a photographic nxing solutioncontaining silver in solution the silver will readily be recovered byelectro-chemical action oi the electro-couple and be deposited on thegauze covered shim brass sheets ll, partly encircling the zinc platu Iand I. This recovery action oi the unit is rather speedy due to the iullexposure oi wing portions I, I oi zinc plates I and 4 to the solution,and such exposure is possible and iacilitated by the angular oiisettingoi wing p rtions I, 'I' with respect to central portions s oi the zincplates.

An electrolytic unit oi this type will recover silver oi pure bullionstandard, particularly, when chemically pure zinc and copper elementsare used, and use oi chemically pure elements eiiects rejuvenation oithe ilxing solution oi a bath in a high degree.

Having thus described our invention:

What we claim is: r

1. An electrolytic unit for reclaiming precious metals irom bathscontaining such metals in solution comprising a strip copper, a pair oizinc plates each having a suriace area at least twice the suriace oisaid strip oi copper, said zinc plates being arranged at opposite sidesoi said copper strip parallel thereto and iormed with wing portionsangularly and outwardly oi!- set with respect to their central portions,layers oi non-conducting porous material spacing said copper strip iromthe central portions oi said sine plates, and cotton gauze coveredsheets oi shim brasscovering the outer suriace oi each oisaidsincplatesandioldedaround theireelyexposedinnersuriaceareasoisaidsincplates.

3. In an electrolytic unit embodying layers oi diiierent metalsseparated irom each other by layers oi non-conducting porous material astrip oicopper,andapairoizinc plates, eachoisaid plates havingapproximately three times the surlution comprising a copper strip, apair oi zinc plates at opposite side oi said copper strip, and aplurality oi interjacent layers oi nonconducting porous material, thezinc plates each having asm'iaceareaatleasttwicethesuriace areaoi thecopper strip and being iormed with wing portions angularly and outwardlyoiiset with respect to the central portions oi said zinc platestoiormopenchannelsatoppositeedgesoisaid unit and facilitate intimatecontact oi said copper strip and zinc plates with a solution into whichsaid unit has been placed.

JOHN M. 13. JAMES E. MASON.

